Urban environments exhibit narrower environmental temperature profiles, with increases in mean temperature compared with natural environments. In this context, urban populations will exhibit narrow thermal tolerance ranges, driven by a reduction in the ability to tolerate low temperatures and a more modest increase in the ability to tolerate high temperatures. Also, in the case of morphology, body size may vary with temperature in such urban-natural systems. Generally, there is a lack of knowledge on adaptive intraspecific variation in cold tolerance and body size of Collembola in these contrasting environments. In this study variation in these traits were explored in the common parthenogenetic springtail Isotomiella minor (Schäffer, 1896). The populations from warm urban habitats to tolerate lower temperatures less well than those inhabiting colder natural habitats was expected. Furthermore, whether the body size of populations may be related to habitat temperature was also explored. Significantly higher cold resistance was observed in the natural populations of I. minor compared to the populations from urban sites. The difference in the LD₅₀ values between the populations also corresponded with their survival-temperature curves. The LD₅₀ values correlated significantly with the soil temperature means at the sites. The body size of the Isotomiella populations decreased significantly with increasing soil temperature. Since elevation was the primary driver influencing temperature differences at sites, urbanisation effect could not be fully specified in our study. In conclusion, soil temperature, in combination with other environmental factors, plays a crucial role in the cold tolerance and body size of Isotomiella minor in urban and natural environments.